This invention relates to new and useful improvements in grinding wheel dressing means and is particularly applicable to dressing means for saw chain grinding wheels.
A saw chain extensively in use employs chisel bit type cutter elements. These cutter elements have angled cutting surfaces that are ground by a grinding wheel properly shaped so as to have a pair of grinding surfaces extending in top and edge tapered planes. The most efficient angle of the cutting surfaces of a saw chain is predetermined and to maintain such efficiency, these angles must remain constant as the wheel wears to a smaller diameter. If the wheel is dressed too thin, the side plate of the tooth will be ground too thin which does not leave clearance for the wood chips to be removed whereby the chain will bind in the cut. If the wheel is dressed too thick, the side plate of the tooth will be ground out too much and does not leave the portion of the tooth, namely, the gullet, that holds the tooth upright and keeps it from trying to lay over in the cut. The gullet guides the tooth through the wood.
Grinding wheel dressing means now in use employ individually operable dressing heads for individually dressing each of the grinding surfaces of the wheel. Without a scale for a guide, dressing is accomplished by eye, or in other words, what looks right. If too much dressing occurs on the top surface, the edge surface becomes too thin and then it is required that the top surface be redressed for correct thickness. Likewise, if too much dressing occurs on the edge surface, the wheel at the top surface becomes too thick and thus the top surface has to be redressed to thin it back down. Such of course is wasteful of the grinding wheel surfaces.